The term "natural" has been modified and expanded over the course of a century or so. Because of this progression in the number of potential uses and variations it is not always easy to spot when the term is being intentionally misuses or when it is simply a poor choice of wording. To get an idea of just how diverse the term has become I've copied the definition from Chambers 21st Century Dictionary,
1. normal; unsurprising; 2. instinctive; not learnt; 3. born in one; innate a natural talent; 4. being such because of inborn qualities Christian is a natural communicator; 5. said of manner, etc: simple, easy and direct; not artificial; 6. said of looks: not, or apparently not, improved on artificially; 7. relating to nature, or to parts of the physical world not made or altered by man natural sciences areas of natural beauty; 8. following the normal course of nature died a natural death; 9. said of materials, products, etc: derived from plants and animals as opposed to man-made natural fibres; 10. wild; uncultivated or uncivilized; 11. related to one by blood one’s natural parents; 12. euphemistic see illegitimate his natural son; 13. music not sharp or flat.
1. colloquial someone with an inborn feel for something She’s a natural when it comes to acting; 2. a person or thing that is the obvious choice for something; 3. someone or something that is assured of success; a certainty; 4. music (a) a sign (♮) indicating a note that is not to be played sharp or flat; (b) such a note.
naturalness noun a natural state or quality; being natural.
[14c: from Latin naturalis from natura nature.]"
So, depending on context and intent there are any number of correct ways that the word can be used. There are still plenty of blatantly wrong ways to employ the term. One of the most common and irritating ones I routinely come across is its misuse as a synonym for "good" (as in morally good). There is nothing in the above definition that places a moral value on Natural. Being natural does not describe something in terms of moral values. Anything natural can be good, bad, both, or neutral. Unnatural often gets a similar treatment and is just as irksome.